1 files changed, 20 insertions, 0 deletions
diff --git a/CLI/rust/src/game_of_life/opts.rs b/CLI/rust/src/game_of_life/opts.rs
index 5e52715..a0ed34b 100644
--- a/CLI/rust/src/game_of_life/opts.rs
+++ b/CLI/rust/src/game_of_life/opts.rs
@@ -46,4 +46,24 @@ pub(crate) mod validators {
             Err(e) => Err(e.to_string()),
         }
     }
+
+    #[cfg(test)]
+    mod is_positive {
+        use super::*;
+
+        #[test]
+        fn positive_value() {
+            assert!(is_positive("1337").is_ok());
+        }
+
+        #[test]
+        fn negative_value() {
+            assert!(is_positive("-1337").is_err());
+        }
+
+        #[test]
+        fn string_value() {
+            assert!(is_positive("not a number").is_err());
+        }
+    }
 }